U.N. peacekeepers have deployed to a city in the eastern Democratic Republic of Congo after clashes between armed groups and the Congolese army.

The U.N. peacekeeping mission in Congo, MONUSCO, said it sent troops to Uvira to protect civilians and deter any attack on the city, located near the Burundian border, on the northern end of Lake Tanganyika.

A reporter for VOA's French to Africa service said a militia known as the Mai Mai Yakutumba sent four motorboats filled with armed men over the lake to attack a bridge early Thursday.

The head of the Uvira district, Sephanie Milenge Matundanya, said army troops drove the militiamen out of the city and several villages they had occupied.

A local resident said U.N. helicopters were in the area but that the city was calm later in the day.

Eastern Congo has been wracked by violence for years as the government and various militias fight for control of rich mines that produce gold and coltan, a material used in mobile phones.

Tensions have run even higher due to the failure of the DRC's government to organize elections and President Joseph Kabila's refusal to leave office at the end of his term last December.

MONUSCO said it has sent its deputy force commander to oversee the situation around Uvira.

The head of MONUSCO, Maman Sidikou, said in a statement he "urged the armed groups to immediately cease this hostility, including all forms of violence against constituted authority and innocent civilians."

VOA's French to Africa Service and Swahili Service contributed to this report.